Risa Niigaki(新垣 里沙Niigaki Risa, born October 20, 1988 in Yokohama, Kanagawa, Japan) is a fifth generation member of the Japanese pop group Morning Musume as well as the sub-leader. She joined Morning Musume in 2001 along with Ai Takahashi, Asami Konno and Makoto Ogawa. She grew up in Yokohama after moving there at age six. As of 2009, she is the longest serving sub-leader of Morning Musume.